Updated at 11:41 a.m. ET
Longtime Democratic Rep. Barney Frank of Massachusetts plans to retire after his term expires at the end of next year.
The 16-term congressman plans to announce his decision not to run for re-election in 2012 at a press conference in Newton, Massachusetts at 1 p.m. ET today.
Frank first took office in Massachusetts' 4th congressional district in 1981 and served as chairman of the House Financial Services committee from 2007 to 2011, during which time he spearheaded work on the landmark Dodd-Frank financial regulation legislation, which rewrote the rules for Wall Street after the 2008 financial crisis.
Frank, considered the most prominent gay politician in the United States, is known as an outspoken liberal with a sharp tongue. His liberal positions have made him a of conservatives, particularly after the passage of the Dodd-Frank Act.
The congressman faced one of his toughest re-election bids in 2010, when conservative groups madeto back his challenger, Republican Sean Bielat. Frank defeated Bielat, 53 percent to 43 percent.
He faced a potentially more difficult race in 2012, now that the 4th district has been redrawn to include more conservative towns. Frank had raised just over $760,000 for his next campaign.